What type of contact is referred to as the holding contact?

The term "holding contact" refers specifically to a type of contact in electrical control circuits, particularly in relation to relays and contactors. A holding contact is responsible for maintaining the state of a circuit once it has been activated. When a control device, like a switch or relay, is engaged, the holding contact closes and keeps the circuit energized even after the initiating device is disengaged. This is particularly useful in applications where continuous operation of a device is required without needing to repeatedly engage the original signal or input mechanism.

For instance, in a motor control circuit, when the start button is pressed, it energizes the relay, and this relay can be designed to include a holding contact that allows the relay to remain energized even after the start button is released. The importance of a holding contact lies in its ability to provide a practical means of maintaining power to a load without continuous operator input, enhancing both convenience and efficiency in electrical systems.